Carbon dioxide levels reach new global milestone
Worldwide atmospheric levels of carbon dioxide, the gas scientists say is most responsible for global warming, surpassed 400 parts per million for the month of March, the National Oceanic and Atmospheric Administration said Wednesday.
Though there have been readings this high before, this is the first time that global concentrations of the CO2 gas have averaged 400 ppm for an entire month. Measurements of carbon dioxide in our atmosphere began in the late 1950s.
NASA Goddard Space Flight Center (CC BY 2.0)